JP2005-022079A discloses an electric stapler in which a forming portion having a forming plate, a driver portion having a driver plate, an anvil, a crown plate and the like are disposed so as to be opposed to a clincher portion having a movable clincher with a paper table between them. In this electric stapler, the forming portion and the driver portion are moved to the clincher portion side, a staple is bent into a U shape with the forming plate and is struck out by the driver plate to cause the leg portions of the staple to penetrate through papers on the paper table, and this leg portions are bent with the movable clincher, thereby binding the papers.
In the electric stapler, the driver portion having the driver plate, the forming portion having the forming plate, the anvil, the crown plate and the like are configured to be separate from each other. Therefore, when dealing with a staple jam in the driver portion, when replacing the parts, or upon maintenance of the parts, there has been a problem that it takes time and labor to detach and to attach the driver portion and others.
That is, when there is something wrong with mechanism portions involved with a staple striking operation, e.g., the driver plate, the forming plate, the anvil or the like, various parts of the mechanism portions need be detached separately. Thus, there has been a problem that it is difficult as well as takes time and labor to address the staple jam, or to replace and maintenance the parts. Also, when it is necessary to change a crown width of a staple in accordance with the number of sheets of papers to be bound, a replacing work of the parts is troublesome. Further, because the individual parts are taken apart into pieces, it is onerous to manage and keep the parts.
If the driver portion and forming portion are structured as an integral body in order to enhance the maintenance thereof and to easily change the crown width in accordance with the number of sheets of papers to be bound, it is necessary to form a staple passage in the structure. However, when a trouble such as a staple jam occurs inside the staple passage portion, it takes much time and labor for repairing.
Further, if it is necessary to shift the positions of the driver portion, the forming portion or the like in the vertical and/or horizontal directions to detach them, it is difficult to understand the procedure of such detaching operation. Also it is necessary to provide a play in a main body side casing which supports a stapler mechanism.
In addition, since the forming portion, the driver portion and the like need be operated at their respective independent timings, a plurality of drive means, i.e., a plurality of drive parts such as drive cams or drive links, becomes necessary. In such a case, there is a disadvantage in terms of a machine size, the number of parts and the manufacturing cost of the electric stapler. JP2002-46083A and JP2005-35151A disclose an electric stapler operable to carry out a large amount of binding processing by employing a staple magazine inside which staple sheets, each having parallel adhered linear metal lines, are superimposed on top of each other and accommodated. This electric stapler is widely used as a stand-alone-type electric stapler or such that it is incorporated in a copying machine or the like.
The lower-most-layer one of the staple sheets superimposed inside the staple magazine is sent forward by a feed pawl provided in the stapler feed mechanism of the electric stapler, and a front linear staple is bent formed substantially into a U shape by the forming portion. The formed staple is introduced into a staple ejecting passage at the leading end of a staple feed passage. The staple inside the staple ejecting passage is struck out therefrom by a driver, and the leg portion of a staple having penetrated through papers is bent by a clincher provided on the side of the lower surface of the papers, whereby the papers are bound.
In a stapler, the precision of the staple ejecting passage has an influence on the binding performance and the rate of occurrence of the staple jam. When, the front-and-back direction width of the staple ejecting passage has no room with respect to the line diameter of a staple, the friction resistance when jetting out the staple is large, resulting in the lowered binding performance. On the other hand, when the room is excessively large, the attitude of the staple is disturbed when it is jetted out, whereby the staple is deformed within the jet passage and thus the staple jam is easy to occur. This requires high precision in the relative position relationship between the staple exit of the stapler main body on the staple magazine side and the staple ejecting mechanism including the forming portion, anvil, driver and the like. However, variations are easy to occur due to the forming allowance and assembling error between the mutually related parts thereof, and also, when breaking into parts or replacing the staple ejecting mechanism portion for maintenance, there is a fear that the relative position precision can be impaired.